According to existing electrophotographic techniques, images are formed by transferring toner images developed on surfaces of electrophotographic photosensitive members onto paper or the like.
Even after toner images have been transferred onto paper or the like, some toner usually remains on surfaces of the electrophotographic photosensitive members and thus removal of the residual toner becomes necessary.
In order to remove the residual toner, a cleaning section that scrapes off the residual toner by pressing a cleaning blade composed of an elastic material such as rubber against a surface of an electrophotographic photosensitive member and recovers the residual toner that has been scraped off into an opening facing the electrophotographic photosensitive member has been widely employed.
However, when such a cleaning section is employed, some of the residual toner that has been scraped off tends to scatter from both ends of the cleaning blade instead of being recovered at the opening.
In order to effectively suppress scattering of the residual toner from both ends of the cleaning blade, a cleaning section (first cleaning section) has been proposed in which side seals are integrally attached to both ends of the cleaning blade.
Another cleaning section (second cleaning section) has also been proposed which includes a cleaning blade constituted by a smooth and flat porous main body composed of a fluorocarbon resin having good slidability and a sponge-like elastic body superimposed on the porous main body. With this cleaning section, deterioration of the side seals rarely occurs even when the side seals are pressed against the surface of the electrophotographic photosensitive member and a good sealing function is achieved.
However, in the first cleaning section, although the cleaning blade and the side seals are integrated with one another, their contact pressures against the surface of the electrophotographic photosensitive member differ and the balance between the respective contact pressures is left unadjusted. This causes the cleaning blade and the side seals to easily curl up, thereby only accelerating toner scattering. In the second cleaning section, because the slidability of a portion of the side seal where the side seal contacts the electrophotographic photosensitive member has been enhanced, the residual toner easily slips beneath the side seals. This renders it difficult to suppress toner scattering.